If you think about it, college students happen to be such a great captive market for the textbook sellers. Any time a professor prescribes a certain textbook, the entire class has no choice but to go out and get a copy. There never was a more angry captive market than the college students we have today. All of that could go away with a bunch of great new services that have come up, offering college textbook rentals - services with names like Chegg and CourseSmart - in addition to Amazon and Barnes & Noble. Renting textbooks, you can usually save 75% off the cost of what it would take it by textbook outright. But these are e-books that they rent out. If you want the real thing, the National Association of College Stores says that just about every college bookstore this year is ready to enter the college textbook rentals business.
Students have always been able to sign up for some kind of buyback program where they buy new textbooks at the beginning of the semester, paying the full $150 or whatever for it; they get to sell it back to the college bookstore or wherever for $5 at the end of the semester. It tends to not be quite satisfying. On Amazon, the typical college textbook sells for about $200. If you went for the e-book edition to keep, you’d pay $100 for it. If you just wanted to rent the e-book version, you'd just have to pay about $50. That's a great saving.
College textbook rentals aren't for everyone though. The rental programs tend to only keep titles that have mass-market appeal. If your professor happens to prescribe a kind obscure title, renting won't be an option. The rental companies have a reason for doing this, of course. Any time they buy a book to rent it out, they can only do it once per semester. To make a profit on a book, they need to be able to rent it out at least four times. They couldn't be sure of being able to do so if they went and got obscure titles.
Sometimes, renting isn't even the smart choice to make. For instance, what if you have a textbook that you needed the whole year through and not just over the single semester? You might as well go and buy a new textbook for what you would spend on rent. And anyway, a much cheaper option you're likely to have, going to a used books site like Half.com
If you do decide to go with college textbook rentals, you should probably choose paper over e-book. You're likely to save more money.